Wall systems defined by a plurality of upright space-dividing panels are widely utilized in offices and the like to divide large open areas into smaller workspaces. Such wall systems typically employ individual panels which are prefabricated and at least partially factory assembled. Such panels, which may be of floor-to-ceiling height or of lesser height, typically employ a rigid frame to which side cover pads are attached for enclosing the frame and defining the desired aesthetics of the finished wall panel. The cover pads, which may extend the full vertical height of the frame, or which may be a plurality of smaller pads which attach to the frame, typically include a sheetlike or platelike pad substrate which is exteriorly covered by a thin flexible covering sheet to provide for desired functionality with respect to aesthetics, acoustics and the like. Such covering sheet in some instances constitutes a thin flexible vinyl or foil-like material, but more frequently constitutes a thin fabric which is secured to the pad substrate so that the fabric defines the exterior side surface of the assembled wall panel. While constructions of this type are conventionally and widely utilized, the construction of such cover pads and specifically the application of a thin flexible covering sheet such as fabric to the support substrate has long been an undesirably inefficient and costly process requiring a high degree of manual labor and manipulation in order to ensure that the flexible covering sheet is properly attached to its underlying substrate in a manner which ensures proper alignment of the fabric while at the same time avoiding undesired looseness, puckering or wrinkling.
In the construction of upholstered pads or panels, as aforesaid, the substrate in one conventional construction is defined by a thin sheetlike facing pad which for example may be defined by a compressed mat of fiberglass, either with or without a supporting backer, and this facing pad in turn has a rigid ring-shaped rectangular frame fixed to the back side thereof. The frame extends along the peripheral edges of the pad and is contoured to accommodate clips or fasteners which mount the pad to the wall panel frame. This substrate is then covered by the covering sheet which extends across the front face of the facing pad and is manually wrapped around the side edges of the facing pad and frame so as to permit adhesive securement of the covering sheet edges to a rear side of the substrate, typically a rearwardly facing surface on the frame. As noted above, this is a time consuming and hence an expensive manual assembly process.
In an alternative construction of the upholstered pad or panel, a substrate can be defined by a relatively rigid platelike member, such as an MDF board, which board has the flexible covering sheet adhered either directly to the front face of the substrate or can have a thin compressible mat such as of fiberglass interposed therebetween, and the edges of the flexible covering sheet are manually wrapped around the edges of the substrate and adhesively secured to the back side thereof. This type construction, which is used as a wall panel pad or as a tack board, also involves significant and costly manual assembly.
Accordingly, it is an object of this invention to provide an improved manufacturing apparatus and process which effects substantial automatic wrapping of the edges of a large, generally flat but thin, article such as a cover pad or panel, namely the wrapping of cover sheet flaps around the edges of a substrate and the adhesive securement of the cover sheet flaps to the edges and back side of the substrate, which apparatus and process results in formation of an upholstered article in a highly automated and efficient process which eliminates the significant manual manipulations and functions normally required.
More specifically, this invention relates to an apparatus which is capable of receiving and manipulating an article, herein referred to as a workpiece, defined by a substrate having a flexible cover sheet adhered to one large side (i.e. front) surface thereof, which cover sheet (for example fabric) is oversized relative to the substrate surface so that the cover sheet has flaps which project outwardly beyond at least side edge faces defined on opposite edges of the substrate. The substrate is preferably supplied to a positioning and sizing device which senses the width of the substrate and properly centrally positions it for feeding into a back wrapping apparatus. The back wrapping apparatus adjusts according to the width of the workpiece being supplied. When the workpiece is supplied to the back wrapping apparatus, the workpiece initially passes adjacent adhesive applicators which apply adhesive to the protruding cover sheet flaps. The workpiece is then fed into a back wrap station whereat roller assemblies disposed adjacent opposite sides of the workpiece are activated and effect movement of the flaps into adhesive and pressed contact with the respective side edge faces of the substrate. Rollers associated with the roller units then move inwardly so that the flaps are bent over and pressed into adhesive engagement with the back side of the substrate in close proximity to the respective side edge faces thereof. The roller units then return to an initial rest position, following which the workpiece is discharged from the back wrapping apparatus and a further operational cycle is initiated.
In a preferred arrangement according to the present invention, the workpiece typically has cover sheet flaps projecting outwardly beyond all four edge faces of a rectangular substrate, so that the workpiece can be fed through the back wrapping apparatus a second time to effect edge wrapping of the remaining pair of opposite side edge faces, or alternatively the workpiece can be fed through a second back wrapping apparatus which operates serially downstream of the first-mentioned back wrapping apparatus.
In the back wrapping apparatus of the present invention, the workpiece is preferably movably supported by a pair of sidewardly-spaced supports which extend lengthwise of the apparatus in the movement direction, and which are disposed uniformly on opposite sides of a lengthwise-extending centerline of the apparatus. The pair of supports mount thereon a pair of sidewardly-spaced but generally parallel conveyor belts having elongate upper belt reaches on which the workpiece is supported. The supports can be synchronously moved inwardly toward or outwardly away from one another to vary the spacing between the belts so as to conform the belt spacing to the width of the workpiece substrate being acted on. The belts move the workpiece initially past a pair of sidewardly-spaced adhesive applicators so that the flaps of the cover which protrude sidewardly from the substrate are sprayed with adhesive throughout the length thereof. Following the adhesive application, the belts move the workpiece into the back wrapping station whereat the belts are stopped to permit stoppage of the workpiece at a predefined location located between the back wrapping rollers. Back wrapping rollers are positioned sidewardly but outwardly adjacent the respective conveyor belts and extend lengthwise therealong and are supported for movement upwardly along and around the edge and respective upper corner of the substrate to effect pressing of the adhesively-coated cover flap into engagement with edge and back sides of the workpiece. The supports additionally have elongate clamp bars movably mounted thereon and individually positioned so that each clamp bar is disposed generally above and extends lengthwise along the respective upper reach of the conveyor belt. The clamp bars are vertically displaceable from a raised clearance position into a lower position for engagement with the substrate to hold it against the belt during upward movement of the wrapping rollers along the side edge faces of the substrate. The clamping bars are raised upwardly away from the workpiece when the rollers are moved inwardly to press the flaps into engagement with the back surface (i.e., the upwardly facing surface) of the substrate.
In the improved back wrapping apparatus, as aforesaid, there is additionally and preferably provided a third elongate conveyor belt disposed generally along the central longitudinal plane and which is moved synchronously with the conveyor belts associated with the sidewardly spaced supports. This third conveyor belt, at the upstream end, is preferably elongated so as to project outwardly to effect driving engagement with the workpiece, as it is fed into the back wrapping apparatus, prior to the workpiece engaging the drive belts associated with the side supports. The upstream projection of the center drive belt preferably overlaps the driving extent of additional drive belts associated with the infeeding and positioning device located upstream of the edge wrapping apparatus so as to provide a smooth and uniform transference of the workpiece from the infeeding apparatus to the edge wrapping apparatus.
This invention also relates to an improved process for effecting edge wrapping of an upholstered article such as a cover pad or panel, which process includes, in a preferred embodiment, many of the operational procedures carried out by the apparatus of this invention, as briefly summarized above, and as explained in greater detail hereinafter.
Other objects and purposes of the invention will be apparent to persons familiar with constructions and processes described herein upon reading the following specification and inspecting the accompanying drawings.
Certain terminology will be used in the following description for convenience in reference only, and will not be limiting. For example, the words “inwardly”, and “outwardly” will refer to directions toward and away from the geometric center of the apparatus or of any designated part or component thereof. The word “forward” will refer to the normal direction of movement of the workpiece through the apparatus, which movement is from left to right in the arrangement illustrated by FIGS. 6-8, 11-12 and 20-21. The words “right” and “left” will be used to reference the sides of the apparatus, in the direction of movement thereof when viewed from the input end, namely, the leftward end in FIGS. 1-3. The words “upstream” and “downstream” will be used in reference to the direction of movement of the workpiece through the apparatus. The words “upwardly”, “downwardly”, “leftwardly” and “rightwardly” may also be used in conjunction with directions as appearing in the drawings. Said terminology shall be deemed to include the words specifically mentioned, derivatives thereof, and words of similar import.